Flat Roof Core Cut Test
A core cut test is a useful and simple diagnostic tool for your flat roof system. A core cut test uses a tool called a core cutter to extract a sample of a building’s existing flat roof system.
Why do a flat roof core cut test?
DETERMINE WHAT MATERIALS MAKE UP A FLAT ROOF SYSTEM
It is difficult and often impossible to determine the composition of a roof system by visual inspection alone – that is – without penetrating the membrane. A core cut sample provides a sample of these materials and how they are installed.
DETERMINE THE MOISTURE CONTENT OF A FLAT ROOF SYSTEM
The sample from a core cut test allows us to examine the moisture content of the flat roof system- particularly that of the underlying insulation. The moisture content of a flat roof system is a critical indicator of its remaining expected lifetime and of the entire system’s thermal efficiency. As insulation holds more water it loses its ability to insulate. Water underneath the membrane is a contributing factor to the deterioration of the structural deck holding up the roof.
DETERMINE THE CONDITION OF THE TOP-SIDE OF STRUCTURAL DECKING
The presence of water, certain materials, or any combination of the two may lead to deterioration of the deck surface. For example, phenolic insulation, once a popular insulation used in flat roof construction was later found to compromise the integrity of structural steel components when exposed to water. Knowing the condition of the top-side of structural decking is useful information for stakeholders.
When should a flat roof core cut test be done?
A prudent roof estimator always performs a flat roof core cut test prior to beginning any roof replacement or retrofit project. A flat roof core cut test will allow for accurate costing prior to beginning a project, mitigating the chance of unforeseen conditions resulting in “contract extras”. A flat roof retrofit project must always include the detection and removal of “wet” sections of existing flat roof prior to installing the new flat roof system over-top – failure to do so compromises the expected lifetime of the retrofit flat roof.
INTERNAL ROOF LEAK INVESTIGATIONS
If the roof system beneath the flat roof membrane is water-logged it may result in an internal roof leak. An internal roof leak happens when water leaks from the roof system even though it is not raining. This is a frustrating experience for the building owner, tenant, and roofer. A sample from a core cut test can help determine if a building is experiencing an internal roof leak.
FLAT ROOF SURVEY
A core cut test is invasive – it involves breaking the seal of your water-tight flat roof membrane. Alternative, non-invasive, flat roof assessment and inspection tools and methods exist today that often provide the same or similar information as that of a core cut test. When these options exist- it is best to opt for them instead.